skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Macroscopic superposition and entanglement for displaced thermal fields induced by a single atom

Abstract

We show that a cavity field can evolve from an initial displaced mixed thermal state to a macroscopic superpositions of displaced thermal states via resonant interaction with a two-level atom. As a macroscopic system (meter) is really in a mixed state before coupling with the microscopic system at some temperature, our result is important for studying the quantum measurement problem and decoherence under real conditions. For the two-mode case, entanglement of displaced thermal states between the modes can be obtained.

Authors:
 [1]
+ Show Author Affiliations
  1. Department of Electronic Science and Applied Physics, Fuzhou University, Fuzhou 350002 (China)
Publication Date:
OSTI Identifier:
20982245
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.75.032114; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ATOMS; COUPLING; INFORMATION THEORY; INTERACTIONS; IONS; MIXED STATE; PHOTON-ATOM COLLISIONS; QUANTUM ENTANGLEMENT; TRAPPING

Citation Formats

Zheng, Shi-Biao. Macroscopic superposition and entanglement for displaced thermal fields induced by a single atom. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.032114.
Copy to clipboard
Zheng, Shi-Biao. Macroscopic superposition and entanglement for displaced thermal fields induced by a single atom. United States. doi:10.1103/PHYSREVA.75.032114.
Copy to clipboard
Zheng, Shi-Biao. Thu . "Macroscopic superposition and entanglement for displaced thermal fields induced by a single atom". United States. doi:10.1103/PHYSREVA.75.032114.
Copy to clipboard
@article{osti_20982245,
title = {Macroscopic superposition and entanglement for displaced thermal fields induced by a single atom},
author = {Zheng, Shi-Biao},
abstractNote = {We show that a cavity field can evolve from an initial displaced mixed thermal state to a macroscopic superpositions of displaced thermal states via resonant interaction with a two-level atom. As a macroscopic system (meter) is really in a mixed state before coupling with the microscopic system at some temperature, our result is important for studying the quantum measurement problem and decoherence under real conditions. For the two-mode case, entanglement of displaced thermal states between the modes can be obtained.},
doi = {10.1103/PHYSREVA.75.032114},
journal = {Physical Review. A},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
Copy to clipboard
Journal Article:
DOI:  10.1103/PHYSREVA.75.032114
Other availability
Find in Google Scholar Find in Google Scholar
Search WorldCat Search WorldCat to find libraries that may hold this journal
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

  • ; ; ; ... - Physical Review. A
    We discuss the generation of a macroscopic entangled state in a single atom cavity-QED system. The three-level atom in a cascade configuration interacts dispersively with two classical coherent fields inside a doubly resonant cavity. We show that a macroscopic entangled state between these two cavity modes can be generated under large detuning conditions. The entanglement persists even under the presence of cavity losses.

  • ; ; - Physical Review. A
    We theoretically examine two-color photoassociation of a Bose-Einstein condensate, focusing on the role of rogue decoherence in the formation of macroscopic atom-molecule superpositions. Rogue dissociation occurs when two zero-momentum condensate atoms are photoassociated into a molecule, which then dissociates into a pair of atoms of equal-and-opposite momentum, instead of dissociating back to the zero-momentum condensate. As a source of decoherence that may damp quantum correlations in the condensates, rogue dissociation is an obstacle to the formation of a macroscopic atom-molecule superposition. We study rogue decoherence in a setup which, without decoherence, would yield a macroscopic atom-molecule superposition, and find thatmore » the most favorable conditions for said superpositions are a density {rho}{approx}10{sup 12} cm{sup -3} and temperature T{approx}0.1 nK.« less

  • ; ; ; ... - Physical Review. A
    The high resilience to decoherence shown by a recently discovered macroscopic quantum superposition (MQS) generated by a quantum-injected optical parametric amplifier and involving a number of photons in excess of 5x10{sup 4} motivates the present theoretical and numerical investigation. The results are analyzed in comparison with the properties of the MQS based on |{alpha}> and N-photon maximally entangled states (NOON), in the perspective of the comprehensive theory of the subject by Zurek. In that perspective the concepts of 'pointer state' and 'environment-induced superselection' are applied to the new scheme.

  • ; ; ; ... - Physical Review. A
    We discuss what can be inferred from measurements on evolving one- and two-qubit systems using a single measurement basis at various times. We show that, given reasonable physical assumptions, carrying out such measurements at quarter-period intervals is enough to demonstrate coherent oscillations of one or two qubits between the relevant measurement basis states. One can thus infer from such measurements alone that an approximately equal superposition of two measurement basis states has been created during a coherent oscillation experiment. Similarly, one can infer that a near-maximally entangled state of two qubits has been created part way through an experiment involvingmore » a putative SWAP gate. These results apply even if the relevant quantum systems are only approximate qubits. We discuss applications to fundamental quantum physics experiments and quantum-information processing investigations.« less

  • ; ; ; ... - Applied Physics Letters; (USA)
    Damage formed by BF{sup +}{sub 2} and As{sup +} implantations in Si was evaluated quantitatively. The density of displaced atoms ({ital D}{sub da}) was determined from 1.5 MeV He{sup +} Rutherford backscattering spectrometery. {ital D}{sub da} increased from 4.7{times}10{sup 16} to 1.6{times}10{sup 17} cm{sup {minus}2} with the dose increased from 6.0{times}10{sup 13} to 1.3{times}10{sup 14} cm{sup {minus}2}. However, {ital D}{sub da} saturates at around 4{times}10{sup 17} cm{sup {minus}2} for all doses above 5{times}10{sup 14} cm{sup {minus}2}. The thermal wave signal intensity shows the same dose dependence as {ital D}{sub da}. This result shows that thermal wave signal intensity has amore » close relation with the density of displaced atoms formed by ion implantation. Therefore, quantitative damage monitorings can be achieved by thermal wave intensity measurements. Also, the variation of thermal wave signal intensity with ion implant energy was studied.« less